Wiring Schematic?

[Steve N Sal]

Does anyone know where I could obtain a wiring schematic for the rear towing plug for a W22 chassis. The problem is, that on my unit I can get the brake lights, hazards and turn signals to work on the tow dolly but not the running lights. I guess I should mention the lights on the dolly are all LED. At the plug I have four (4) white wires one green or gray wire and a blue wire. Now if you don't think that determining wich one was the ground it was a nightmare.
The blue I have determined does absolutely nothing so I taped it for protection and put it to the side.
The green or gray will provide solid 12 volts when turning on the clearance lights, as well as one of the other white wires. So I have a white and green or gray that provide solid 12 volts but when I put them on the plug and plug the dolly harness in, NO lights. I can hook the dolly to a remote battery or my pickup truck and everything functions properly. The dealer said I must have a bad ground but if I did why do the turns signal, brake lights and hazards work?
I tried to follow the cables back through the plastic conduit to just behind the gas tank, where there they seem to run back and forth from side to side of the moho and then are all taped together.
I would think that there must be somewhere at the very rear of the coach where I could obtain all that is needed to fix this problem. I have called Newmar but all they gave me was the wiring schematic for the rear plug which I already have.
Any suggestions as to where I might be able to look? Thanks

[oemtech]

You should have the same setup I have. There are 3 wires wound up under the dash that you can use.

[Steve N Sal]

Dale,

I appreciate the reply. I'll have to look under the dash to see if they are there. I don't remember seeing them the last time under there when this whole nightmare started. Do you possibly know how far back on the chasis they ran those wires. In being under the coach I don't recall anything under there as well. Thisis a real pain in A_ _! I still don't understand why the turns, hazards and brake lights work if I have a bad ground. Like I had mentioned I have two (2) wires back there that are controlled from the fuse box up under the hood (both 5A fuses) marked R and L tail lamps that I can get a steady 12 volts but nothing on the dolly. Go figure.
Thanks, Steve

[oemtech]

The info above is from my Newmar documentation. The 7 pin connector diagram is my creation using Word.

As far as I know the wires rolled up under dash run all the way to the 7 pin connector and are attached to pins 2, 4, & 7. A bad ground will drive you nuts. I run ground wires and do NOT depend on any kind of frame ground.

Also, don't depend on the color of the wires in the diagram.

[DAN L]

are the running lights led's too? if they are incandescent, they draw much more current than led's and require a good ground to operate. imho making your own separate ground should fix you problem.

[Steve N Sal]

Here's the kicker that I failed to mention. The three (3) light bar in the center of the dolly which has incadescent lamps and the plate lamp also incadescent work with NO problem. The problem is they can't be seen once the car is on the dolly. I was told that the LED's draw more than the incadescent.

[oemtech]

Replace the LED's with incandescent lights for testing.

[edgray]

Quote:

Originally Posted by Steve N Sal Here's the kicker that I failed to mention. The three (3) light bar in the center of the dolly which has incadescent lamps and the plate lamp also incadescent work with NO problem. The problem is they can't be seen once the car is on the dolly. I was told that the LED's draw more than the incadescent.

whoever told you that is dead wrong. It is just the opposite. LEDs draw so little current that they can create problems in systems which require a higher level of resistance to operate correctly. ED

[Steve N Sal]

I'm appreciating everyones input but I'm still confused as to why the turn, hazard and brake lights (all LED) are working and not the running lights (also LED) except for that three light bar and plate light. The lights that work at any given situation are still operating off the same ground. ?????????? @&$%^>*<^#!!!!!

[BellaBo]

LED's are "light emitting diodes" and typically will only light if the polarity of the voltage is correct. It might be that somehow the connections on your running and plate leds are reversed.

You might try to ISOLATE them and connect a external battery source, even a 9volt battery, connect the wires to the battery then reverse them to see if they work.

Just a suggestion.
Good luck,

[mfire1339]

I believe led's are voltage sensitive as well as polarity sensitive.

Mike

[DriVer]

Quote:

Originally Posted by mfire1339 I believe led's are voltage sensitive as well as polarity sensitive.

Mike, Light emitting doides (LED) only flow current in one direction like all other diodes. So you are correct they are polarity sensitive.

Voltages on the other hand when in a vehicle situation would call for products that are within the 12 volt operational range so I would expect that it would not be a major concern.